A diffuser assembly commonly contains a main body having an air intake port and at least one air exhaust port. A diffuser is then attached to each air exhaust port so that air fed through the air intake port exits out the air exhaust port into the diffuser and then generates bubbles by passing through the perforated membrane or porous material of the diffuser. Because air is less dense than water, the diffuser assembly is usually buoyant when filled with air, so that a ballast member can be attached to the main body in order to cause the diffusers to sink to the bottom of the tank so that the largest volume of water in the tank can be aerated.
If the diffusers are at the bottom of the tank and need service (including repair) or maintenance, the tank will need to be drained so that maintenance workers can gain access to the diffusers. This can be quite hazardous because of the presence of noxious fumes in the tank. Further, it takes time to drain and refill the tank, which makes the tank inoperable during draining, maintenance and servicing, and refilling. Because the tanks are often underground and because the tanks contain wastewater, openings for access into the interior of the tank are often placed on the top, above the water level. If the openings were below the water level, then wastewater may leak out of the tank through the opening, and the tank would need to be drained at least below the level of such an opening in order to service and maintain the diffusers.
Diffusers are typically elongated and narrow in order to increase the area through which air is being diffused. If more diffusers are necessary, then additional elongated diffusers are normally added parallel to and spaced apart from other diffusers.
It is therefore desirable to be able to service and maintain diffusers that are in the bottom of a wastewater treatment tank without needing to drain and refill the tank. It is also desirable to be able to perform such servicing and maintenance using only a small opening in the top of the tank, above the water level.